Computer graphic technology has been significantly developed in the creation of non-realistic images, such as cartoons or artistic images, as well as existing photorealistic images. The rapid expansion of a digital content market, such as movies, animations, television (TV), games, or the like, has given prominence to the non-realistic images mentioned above. In particular, recently, various attempts to implement traditional drawing techniques, such as watercolor, or oil painting, using a computer-based virtual canvas have been made.
Meanwhile, typical watercolor rendering researches may be broadly classified into two categories. The first is a method in which a physical model that demonstrates the interaction of paints, water, and paper and the movement of watercolors is calculated through a simulation. The second is to obtain the watercolor image effect by applying an image processing technique without the use of a physical model.
The physical model, in general, may express the movement of watercolors and water by introducing fluid simulation equations, such as, for example, the Navier-Stokes Equation, the Lattice Boltzmann Equation, or the like. The methods that do not use the physical model may introduce a variety of image processing techniques to synthesize the results in the watercolor style. For example, a texture may be made in advance rather than expressing the movement of watercolors through a complicated simulation, and when creating the image, the texture is synthesized with a brush stroke to create a final image, or the edge detection technique may be used to simulate the phenomenon in which the watercolors agglomerate at the edge of the area that is painted in watercolors.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.